From 172397e6e508a97fc87a4657182701bc82904277 Mon Sep 17 00:00:00 2001
From: Bernhard Reiter <Bernhard Reiter@git.wordpress.org>
Date: Thu, 14 Sep 2023 08:52:19 +0000
Subject: [PATCH] Themes: Inject `theme` attribute during serialization.

Rather than using `_inject_theme_attribute_in_block_template_content` to inject the `theme` attribute into all Template Part blocks found in a given file-based Block Template, introduce a new function called `_inject_theme_attribute_in_template_part_block`, and use that as second argument to `serialize_blocks()` (introduced in [56557]) in order to inject said attribute during tree traversal for serialization.

This allows for a more modular approach that will eventually be extended to implement automatic insertion of hooked blocks.

Note that we're guarding `_build_block_template_result_from_file()` (i.e. the callsite of `_inject_theme_attribute_in_template_part_block` and previously of `_inject_theme_attribute_in_block_template_content`) against regressions through additional unit test coverage added in [56562].

Props @gziolo.
Fixes #59338. See #59313.
Built from https://develop.svn.wordpress.org/trunk@56578


git-svn-id: http://core.svn.wordpress.org/trunk@56090 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/block-template-utils.php | 24 +++++++++++++++++++++++-
 wp-includes/version.php              |  2 +-
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/wp-includes/block-template-utils.php b/wp-includes/block-template-utils.php
index b8538ee3b4..460372b8cc 100644
--- a/wp-includes/block-template-utils.php
+++ b/wp-includes/block-template-utils.php
@@ -513,6 +513,26 @@ function _inject_theme_attribute_in_block_template_content( $template_content )
 	return $template_content;
 }
 
+/**
+ * Injects the active theme's stylesheet as a `theme` attribute
+ * into a given template part block.
+ *
+ * @since 6.4.0
+ * @access private
+ *
+ * @param array $block a parsed block.
+ * @return array Updated block.
+ */
+function _inject_theme_attribute_in_template_part_block( $block ) {
+	if (
+		'core/template-part' === $block['blockName'] &&
+		! isset( $block['attrs']['theme'] )
+	) {
+		$block['attrs']['theme'] = get_stylesheet();
+	}
+	return $block;
+}
+
 /**
  * Parses a block template and removes the theme attribute from each template part.
  *
@@ -565,7 +585,6 @@ function _build_block_template_result_from_file( $template_file, $template_type
 	$template                 = new WP_Block_Template();
 	$template->id             = $theme . '//' . $template_file['slug'];
 	$template->theme          = $theme;
-	$template->content        = _inject_theme_attribute_in_block_template_content( $template_content );
 	$template->slug           = $template_file['slug'];
 	$template->source         = 'theme';
 	$template->type           = $template_type;
@@ -589,6 +608,9 @@ function _build_block_template_result_from_file( $template_file, $template_type
 		$template->area = $template_file['area'];
 	}
 
+	$blocks            = parse_blocks( $template_content );
+	$template->content = serialize_blocks( $blocks, '_inject_theme_attribute_in_template_part_block' );
+
 	return $template;
 }
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 1840b60adc..255acf5f1c 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.4-alpha-56577';
+$wp_version = '6.4-alpha-56578';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.